Saturday, January 17, 2015
All Frames Are Part of The Boat Now
After several weeks of false starts and measures and re-measures, I finally got to the place where I felt confident that I could glue frame 6 into position. Since the last posting, the one remaining area of measurements I was not sure about was fore and aft measurements and how the frame corners would match up to the sheer and chine battens.
I had decided to try a temporary batten wrapped around the frame corners to see how they matched up. Since I didnt have the chine or sheer lumber yet, I elected to use the temporary cedar batten I purchased several months ago.
The amount of bend this would have to make to get from the breasthook to frame 6 would be quite severe. I figured that if I simply tried to bend this, the wood would break. I knew of two techniques to get around this problem. One involves steaming the wood but requires a source of steam and something to place the part into while it is steaming. Since I was still trying to save for lumber, I wanted to avoid this approach for now rather than purchase a steamer.
The second technique involves wrapping the lumber in towels and pouring boiling water over it, bending the part as much as possible, letting it set for awhile, and then repeating the process until the desired bend is reached. Once that point is reached, the wood is held in the bent position until it has dried out. It should then retain most of that bend and be much easier to get into position.
I had another issue that complicated this test however. The lumber to be bent is very long (16 feet) and initially it sticks out at an angle from the boat. Since I have very limited room on both sides of my boat, I had to rearrange things a bit to get enough room for the lumber. Unfortunately, when I get to the real lumber, this process will only work for one side of the boat. The other side simply does not have enough room. I am planning on prebending both pieces on the same side of the boat and then transferring one of them to the side that has limited room.
In the following series of photos, you can see the technique illustrated and how the space to the side was a problem. The batten was clamped into position on the breasthook at the front. At this point, the wood was sticking out to the side considerably. I had to put a slight bend on it even at this point in order to clear my tool box.
I wrapped the bend area with a couple of old towels and placed a baby pool underneath to catch the water. After pouring boiling water on the towels, I started bending the batten towards the boat. With this wood it actually bent quite easily. When I use the mahogany for the real parts, it may take more effort. Anyway, I used a cinder block to hold the part at the bend I wanted. For some reason, I didnt take a picture at that point, but the following picture shows the setup before the bend.
After the towels cooled down, I removed them and let the wood dry out for the remainder of the day and night. The following day I placed frame 6 into position and saw that the frame corners would match up adequately to the bent part.
When I get to this point with the real lumber, I will post additional information explaining the process. But at this point, I felt confident enough to move forward with installing frame 6 permanently.
This installation process required a bit of clean up on the mating surfaces and permanently installing the lower positive locator for the frame. This locator is simply a piece of wood cut with a notch at the correct height that the frame needs to rest at. This part was screwed to the building form. The frame would rest on this and be clamped to it as well. It would positively locate the height and center the frame on the building form.
In order to positively locate the fore and aft measurements and the vertical straightness, I clamped two wax paper covered blocks to the stem. The first photo shows these blocks behind frame 6. The other horizontal block was not used. The second photo shows a drop string to insure the frame was vertically straight. When the frame is vertically straight, the string would line up with the lower part of the frame.
I had decided to try a temporary batten wrapped around the frame corners to see how they matched up. Since I didnt have the chine or sheer lumber yet, I elected to use the temporary cedar batten I purchased several months ago.
The amount of bend this would have to make to get from the breasthook to frame 6 would be quite severe. I figured that if I simply tried to bend this, the wood would break. I knew of two techniques to get around this problem. One involves steaming the wood but requires a source of steam and something to place the part into while it is steaming. Since I was still trying to save for lumber, I wanted to avoid this approach for now rather than purchase a steamer.
The second technique involves wrapping the lumber in towels and pouring boiling water over it, bending the part as much as possible, letting it set for awhile, and then repeating the process until the desired bend is reached. Once that point is reached, the wood is held in the bent position until it has dried out. It should then retain most of that bend and be much easier to get into position.
I had another issue that complicated this test however. The lumber to be bent is very long (16 feet) and initially it sticks out at an angle from the boat. Since I have very limited room on both sides of my boat, I had to rearrange things a bit to get enough room for the lumber. Unfortunately, when I get to the real lumber, this process will only work for one side of the boat. The other side simply does not have enough room. I am planning on prebending both pieces on the same side of the boat and then transferring one of them to the side that has limited room.
In the following series of photos, you can see the technique illustrated and how the space to the side was a problem. The batten was clamped into position on the breasthook at the front. At this point, the wood was sticking out to the side considerably. I had to put a slight bend on it even at this point in order to clear my tool box.
I wrapped the bend area with a couple of old towels and placed a baby pool underneath to catch the water. After pouring boiling water on the towels, I started bending the batten towards the boat. With this wood it actually bent quite easily. When I use the mahogany for the real parts, it may take more effort. Anyway, I used a cinder block to hold the part at the bend I wanted. For some reason, I didnt take a picture at that point, but the following picture shows the setup before the bend.
After the towels cooled down, I removed them and let the wood dry out for the remainder of the day and night. The following day I placed frame 6 into position and saw that the frame corners would match up adequately to the bent part.
When I get to this point with the real lumber, I will post additional information explaining the process. But at this point, I felt confident enough to move forward with installing frame 6 permanently.
This installation process required a bit of clean up on the mating surfaces and permanently installing the lower positive locator for the frame. This locator is simply a piece of wood cut with a notch at the correct height that the frame needs to rest at. This part was screwed to the building form. The frame would rest on this and be clamped to it as well. It would positively locate the height and center the frame on the building form.
In order to positively locate the fore and aft measurements and the vertical straightness, I clamped two wax paper covered blocks to the stem. The first photo shows these blocks behind frame 6. The other horizontal block was not used. The second photo shows a drop string to insure the frame was vertically straight. When the frame is vertically straight, the string would line up with the lower part of the frame.
The only remaining dimensions to positively locate were measured between the frames at the outer edges on both sides of the boat. Keeping these the same would insure that the frame was not rotated around its center vertically. I accomplished this with braces screwed to frame 5 and extending to frame six. These would be clamped into position after I had the frame measurements the same on both sides.
The remainder of the process involved simply applying the epoxy, re-positioning the frame, checking all the measurements and clamping . I had originally intended to screw the braces between the frames to both frames but neglected to allow for the limited height under the frame so I could not get my electric drill under there. That is why I left the clamps in position.
And so, here it is. After several weeks, the last frame is in position.
In other news, Ive ordered the lumber for the chine and sheer battens. I should have that next week sometime. Now that frame 6 is in position, I can move forward with installing those parts, the keel, and the bottom battens. As mentioned previously, that will all be covered at a future date.
And finally, I had the pleasure of another boat builder visiting me over the holiday week. He had driven out here from Florida to visit family in Texas and wanted to stop by to see my project. It is always a pleasure to discuss the boat with other builders.
I hope you all have had a happy holidays and the next time I post, it will be yet another year. I feel confident that I can still meet by next milestone of being ready to fair the boat by the end of January or shortly after that. Take care.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment